David: Can you tell me what reductionism is?

DN: I think reductionism is the idea that from the molecular level you could reconstruct everything: that, in principle, at the molecular level, everything is there that is needed in order to know how your body works, and that cannot be true.

David: But reductionism is very powerful though, isn’t it? You’re not saying, ‘Reductionism, we shouldn’t use it’?

DN: Of course it’s been hugely successful. It was fantastic, and actually it’s given us huge insights, so I’m not an anti-reductionist. I just think that you’ve got to recognise that there is an integrative process occurring in living organisms, and those functional properties, the meaningfulness, if you like, in that function, because, after all, the rhythm of the heart has meaning; that emerges, and you can’t escape from that.

David: Then why are people so wedded to it? Reductionism?

Ard: That’s a good question.

David: I mean, you both mix with scientists all the time. Why are they so…?

Ard: Because it is a powerful thing. The fact is you can…

DN: The power is great, yes.

Ard: The power is great. You can take something, break it in to parts, and you can really understand. For example, you figure out the molecular structure of DNA and suddenly you understand how certain types of genetic information are encoded in a digital form.

DN: Yes.

Ard: I think that’s an experience that when you have it, it’s very natural to think, well, that is so powerful, it must the way of explaining everything. This powerful method is a method we’re going to use, and we’re going to apply it universally.

David: And only that method. That’s…

Ard: But I think Denis’s point is to say, ‘Well, if you just use only that method, then you’re missing something.’

DN: That’s right, exactly.

Ard: It’s not the same as saying that method is wrong, just that the method is not the only method.

DN: Exactly so, and where it goes wrong can be illustrated, because what Crick did after that discovery was to immediately go out to one of the taverns in Cambridge, where he would drink with his friends, and he announced in the tavern, ‘I have found the secret of life!’

Wow! He had not found the secret of life, because if I take the DNA out of a cell and I put it in a Petri dish with as many nutrients as you like, I can keep it for 10,000 years: it’ll do absolutely nothing. It can’t be the secret of life.

Ard: Right, yes, so this gets to the whole argument about, are genes the recipe for life?

DN: Yes, it does, and the problem with this is that… Recipe is not bad, I mean, it’s written down as a recipe, just like a music score is written down as a music score, but the recipe is not the dish.

David: And the score isn’t the music.

DN: And the score is not the music. Precisely. And so it’s the mistake of thinking that because it’s written down, it must be the thing itself.

Ard: Exactly. I think that’s a great way of explaining it: it’s confusing the recipe with the dish.

DN: With the dish.

Ard: And they’re thinking, once you understand the recipe, then you’re done.

DN: Exactly so.

And one of my big problems with the reductionists is not so much that their method has not been extremely powerful. It has been superbly powerful. It is the hubris: the certainty that that’s all there is.